The present invention relates to a device for cutting holes in pipe, and specifically provides such a device for use in the installation of fire prevention sprinkler systems or the like where work must be performed in close or cramped conditions.
Conventional types of hole cutting devices are most commonly used in either new construction, in the remodeling of existing structures, or wherever additions or alterations to water conduits or plumbing systems need to be made. Conventional pipe hole cutting devices include a base portion which is clamped to the pipe so as to be normal thereto, and which has a linear track along an upper end. A travel plate is also provided for reciprocal movement in the track, with the movement manually controlled through a rack and pinion gear mechanism. A power drill is secured to the travel plate so that as the travel plate is moved, the drill may be brought into contacting relationship with the pipe for drilling the hole.
An important drawback of existing hole cutting devices is that they are cumbersome to use effectively in cramped working environments, whether in new or existing structures. A principal cause of this drawback is due to the length of the base and the travel plate. However, mere shortening of the components in conventional devices has not been effective, due to the operational requirements of this type of device.
Another disadvantage of existing devices is the inability to precisely determine the point at which the drill will impact the pipe prior to the securing of the device upon the pipe. Once the device is secured to the pipe, if it is determined that the hole will not be drilled in the specific location, the base must be moved on the pipe. This process is a tedious one, for disassembly of the device and readjustment of the base upon the pipe are often required, and frequently is frustrated by the bulk of the device in combination with the often cramped working environment.
A further drawback of conventional pipe cutting devices is that they include a base portion which is optimally dimensioned for use on a relatively larger diameter pipe from about 21/2" up to 10". However, the existing device has not been effective on smaller pipes having diameters in the range of 1" to 21/2".
Thus, there is a need for a hole cutting device which is compact enough for use in cramped conditions, which is capable of being accurately aligned with the specified location of the hole prior to the final assembly of the device on the pipe, and which is adaptable for cutting holes in smaller diameter pipe.